According to news reports, the proposed zone has been reduced from 3,358 hectares to approximately 128.19 hectares, a reduction of about 96.2%. It covers land parcels across 36 survey-number entries in seven villages.

As on October 13, 2026, the proposal was awaiting the Madras High Court’s consideration. It should not be treated as a confirmed lifting of construction restrictions.

What Is the Pallikaranai Zone of Influence?

The Zone of Influence is surrounding land that can affect the marsh’s water flow and ecological condition. It may include drainage channels, connected water bodies and areas through which rainwater reaches the wetland.

The marsh boundary and its influence zone are different. Reducing the proposed influence zone does not mean that the protected marsh itself has been reduced or opened for construction.

Why Was the Boundary Reconsidered?

TNSWA received 23 representations from landowners, developers and others. This led to reconsideration of private patta land, specific survey parcels, existing buildings and earlier development permissions.

Following court directions, officials met on September 30, 2026, to review the proposed boundary. Their assessment considered historical satellite imagery, water spread, drainage pathways, low-lying land, existing infrastructure and connections to nearby wetlands.

The revised interim proposal was presented before the High Court on October 12, 2026.

CREDAI Supports the Proposed Interim Zone

Senior counsel P.S. Raman, representing CREDAI Chennai, welcomed the proposal. He said TNSWA had completed the exercise quickly and that the proposed interim zone was acceptable to the developers’ association.

CREDAI Chennai was among the petitioners challenging the NGT’s construction restrictions. After hearing the submissions, the judges said they would examine TNSWA’s latest report and pass appropriate orders on October 14, 2026.

The Survey Numbers Proposed for Inclusion

According to the reported TNSWA submission, the following survey numbers and subdivisions could be included in the interim zone:

THE 36 SURVEY NUMBERS

Pallikaranai 23 (1A,2) · 55 (1D2, 1E2, 1F2, 1G2, 2A2, 2B2, 2C2, 2D2) · 80 · 429/2 · 429/3 · 430 · 431/2 (P) · 432/1 · 433 · 434/3 · 453/2C · 657 (1A, 3A1, 3A3, 3A4, 3F, 3G, 3H, 3I, 3J, 3K, 4A3) · 657/1A (P) · 657/1B3 · 657/3A2 · 657/3A3 · 657/3A5 · 657/3B · 657/4C · 658/1A (P) · 658/1B · 688 (P) · 690 (P) · 691 Perungudi 57/1

Sholinganallur 439 (P) · 507/1 · 527 · 602/7 · 602/8

Perumbakkam 537 (P) · 542 (P)

Injambakkam 283 · 284 (P)

Karapakkam 175 (P) · 177 · 189

Okkiyam Thoraipakkam 407 (P)

“(P)” generally denotes part of a survey number. The official survey schedule and boundary map are necessary to establish the exact portion included.

Would Construction Be Allowed Inside the Proposed Zone?

TNSWA has proposed regulating construction according to each site’s scientific and hydrological characteristics, rather than banning it throughout the entire interim zone.

The following are prohibited inside the interim zones:

• Blocking or diverting established inlet channels, outlet channels and natural drains.
• Dumping solid waste or construction debris in drainage pathways.
• Discharging untreated sewage or wastewater into connected watercourses.
• Permanently altering established water connections.
• Highly polluting Red Category industries.

Inside the Proposed Interim Zone: Construction With Conditions

• Construction could be allowed with an NOC from the District Level Wetlands Management Committee.
• Each site would be assessed separately, based on its conditions and effect on water flow.
• Any development works must not block water entering or leaving the marsh, or damage its ecosystem.

How Does the Wider Watershed Fit In?

The cited Citizen’s Charter for the Pallikaranai Watershed, published by the Chennai Wetlands Action Collective and Oorvani Foundation, describes a 306-square-kilometre watershed containing a cascade of 65 major lakes and hundreds of ponds.

It also cites a survey identifying 452 water bodies, of which 165 were reportedly lost.

These figures describe the larger system through which water reaches the marsh. They do not establish that the entire watershed is a legally declared no-construction zone. However, they help explain why environmental concerns extend beyond the proposed interim boundary.

What Should Property Owners Check?

Before buying, rebuilding or planning construction, owners should verify:

• The property’s revenue village, survey number and subdivision.
• Its position on the official wetland and influence-zone maps.
• Whether the schedule includes the whole survey parcel or only a part.
• The latest court order and applicable approval requirements.
• Drainage connections and restrictions affecting the site.

Private patta ownership does not, by itself, establish that construction is permitted. Likewise, a property’s exclusion from the proposed interim zone would not automatically establish its eligibility for building approval.

What Happens Next?

The reports said the High Court was expected to consider orders on October 14, 2026. The interim proposal is separate from the final delineation, which would require scientific assessment, land-record mapping and ground verification under the Wetlands (Conservation and Management) Rules, 2017.

Property owners should therefore distinguish between a proposed boundary, a court-approved arrangement and permission for their individual site.

The Tamil Nadu government’s curbs on construction around the Pallikaranai Marshland have sparked tension between developers and environmental regulators. Following National Green Tribunal (NGT) and Madras High Court interventions, all new building approvals within 1 km of the Ramsar-designated wetland are currently on hold.
The move, though vital for conservation, impacts over 13 revenue villages with thousands of housing units, IT parks, and infrastructure projects already underway.

Timeline of Key Events

Villages and Survey Numbers Impacted

The Wetland Authority’s June 2025 report lists 304 survey and sub-division numbers across seven core revenue villages within the Ramsar site and its influence zone:

• A report says there are “304 survey and subdivision numbers across seven revenue villages: Perumbakkam, Sholinganallur-I, Pallikaranai, Perungudi, Jalladianpet, Injambakkam, Okkiyam Thoraipakkam” falling within the boundary of the Pallikaranai Marshland/Ramsar site.
• The same report flags specific survey numbers for the case in Perumbakkam: “survey numbers 285 and 286 were recorded as patta ‘ryotwari wetlands’.”
• Some NGO allegations list survey numbers 453, 495/2C, 496, 497, 498 as being claimed to fall within the marsh/Ramsar boundary.

In addition, CMDA’s 2025 circular extends the restriction to nearby 15 revenue villages—including Puzhuthivakkam, Madipakkam, Kulathur, Arasankalani, Semmancheri, Karapakkam, Seevaram, and Velachery—categorised as the 1 km influence zone.

Developers’ Pushback

The Builders’ Association of India (BAI) argues that the blanket freeze will disrupt the livelihoods of nearly five lakh residents and stall affordable housing in approved layouts.
State Chairman K. Venkatesan told that the ambiguity in boundary demarcation is punishing ordinary buyers more than errant developers, urging the government to publish clear zone maps before extending bans.

Ecological and Legal Imperative

Environmentalists maintain that the freeze is non-negotiable. Pallikaranai—one of India’s 75 Ramsar sites—absorbs monsoon runoff from the southern suburbs and supports migratory birdlife. Unchecked construction in its floodplain has worsened Chennai’s flooding vulnerability.
Under the Wetlands (Conservation and Management) Rules 2017, final notification of Ramsar boundaries requires:

1. Map publication and 60-day public consultation, then
2. 240-day review period before Gazette notification.
   Until that process ends, the marsh’s official boundary—and permissible building extent—remains unresolved.

Impact on Buyers and the Market

If your plot lies in the 1 km buffer or among the 304 flagged survey numbers, expect delayed or revoked approvals.
Even legally issued permits may be frozen pending boundary confirmation. For transparency, buyers should:

• Obtain the survey number and verify zoning through Verified.RealEstate’s Due Diligence Tool,
• Cross-check with CMDA’s latest wetland restriction map, on Verified.Realestate ,using geo insights map for a better understanding of the area.
• Avoid commitments until the final Wetland Authority notification is out.

Final survey-number list is being verified by the state, and the list is pending official notification.

Sources: TNSWA/DoSS report to NGT; CMDA Office Order no. 7/2025; NGO Arappor Iyakkam complaint